Phycotoxins from dinoflagellates

Abstract

-Dinoflagellates produce many toxic substances throughout the world.Some of these poisons get into human food through the marine food chain to edible shellfish and fish and cause diseases such as paralytic shellfish poisoning and ciguatera poisoning. The structures of two poisons that cause paralysis have been determined and are (a) saxitoxin, the major toxin produced by Gonyaulax catenella and found inCalifornia sea mussels and Alaska butter clams and (b) ll-hydroxysaxitoxin sulfate, the major poison produced by Gonyaulax tamarensis and found in scallops and clams along the New England coast and the Bay of Fundy. These extremely poisonous substances cause paralysis by blocking the passage of sodium ions through nerve and muscle cell membranes. They are quite heat stable at ordinary cooking temperatures, making the food poisoning problem more acute. Poisons from other dinoflagellates produce ciguatoxin and maitotoxin which arebelieved to cause ciguatera poisoning. Another poison causes liver and kidney degeneration. These poisons have been partially characterized..

Detection of Gymnodimine-A and 13-Desmethyl C Spirolide Phycotoxins by Fluorescence Polarization

“…36 Although we have not tested PSP toxins in this fluorescence polarization assay, the method we propose would not detect PSP toxins in shellfish, since they would not be coextracted with cyclic imines because they are not soluble in chloroform. 37 In summary, this paper reports for the first time a new, specific, and fast assay to detect cyclic imines using their interaction with nAChR. Although these toxins are not still regulated, our assay is sensitive enough to detect concentrations higher than 70 µg/ kg in shellfish meat.…”

“…Paralytic shellfish poisoning (PSP) toxins can also co-occur with spirolides, since some strains of the dynoflagellate Alexandrium ostenfeldii have been shown to produce both kinds of toxins . Although we have not tested PSP toxins in this fluorescence polarization assay, the method we propose would not detect PSP toxins in shellfish, since they would not be coextracted with cyclic imines because they are not soluble in chloroform …”

Screening of Paralytic Shellfish Posioning Toxins in Naturally Occurring Samples with Three Different Direct Competitive Enzyme-Linked Immunosorbent Assays

“…Paralytical shellfish poisoning (PSP) is one of the most potent naturally occurring food poisonings. The poison constitutes a group of >20 structurally related toxins produced predominantly by the dinoflagellate Alexandrium () Protogonyaulax) catenella and Alexandrium tamarense; saxitoxin (STX) and neosaxitoxin (neo-STX) are most toxic and more commonly occur in shellfish such as mussels, clams, and other marine animals (Anderson, 1994;Hall et al, 1990;Schantz, 1979). Both STX and neo-STX have also been found to be produced by the freshwater cyanobacterium (blue green alga) Aphanizomenon flos-aquae (Mahmood and Carmichael, 1986).…”

Direct Competitive Enzyme-Linked Immunosorbent Assay for Saxitoxin and Neosaxitoxin

“…The poison constitutes a group of toxins produced predominantly by the dinoflagellate Alexandrium () Protogonyaulax) catenella and Alexandrium tamarense and is primarily encountered in toxic mussels, clams, and other marine animals. Saxitoxin (STX) is one of the major and most potent members in this group of toxins, and at least 20 analogues of STX have been reported (Anderson, 1994;Hall et al, 1990;Schantz, 1979). In addition to dinoflagellates, the freshwater cyanobacterium (blue-green alga) Aphanizomenon flos-aquae is also known to produce STX and neosaxitoxin (neo-STX) (Mahmood and Carmichael, 1986).…”